Plunger lift control



Patented Feb. 11, 1936 UNITED STATES, PATENT OFFICE,

PLUNGER LIFT CONTROL Harold `W. Fletcher and Ralph Neuhaus, Houston,

Tex., assignors to Hughes Tool Company, Houston, Tex., a corporation of Texas Application February 18, i935, Serial No.. 7,107 11 Claims. (Cl. 10S-52) Our invention relates to method of and apparatus for controlling the operation of a plunger lift device.

It is an object of the invention to control the r release of the gaseous uid pressure from the well after the load of liquid is discharged, and to also control the point of entrance of the pressure4 fluid to the eduction tube in the Well.

We aim to provide an installation that is saving in the amount of gaseous pressure fluid necessary for operation and which will also accelerate the operation of the device so that more strokes of the plunger per hour are.` possible.

It is an object to provide a valve, automatically operated by the movement of the plunger,

to control the inlet of the pressure uid below the plunger at a point above the liquid inlet at the lower end of the eduction tube.

The invention also includes the construction of the control valve whereby it functions properly and is adapted to be operated by the plunger. In the drawing herewith, Fig. 1 is a side view partly in central vertical section of a plunger lift installation embodying Vthe invention. Fig. 2 is a transverse section on the plane 2--2 of Fig. 3.

Fig. 3 is a vertical sectional detail of the valve onthe plane 3-3l of Fig. 2.

Fig. 4 is a sectional detail on the plane 4--4 of Fig. 2.

The plunger lift installation shown includes a Well casing I which extends into the well for the desired depth to retain the walls of the well bore. It has a casing head 2 of special construction, having two lateral ports; an inlet port 3 for pressure uid, and an outlet port 4 for .liquid being pumped. Below the outlet port is an inwardly extending flange 5 to t closely about the eduction tube 6 and support the same.

The upper end of-the casing head is closed by a cap 'I which has an axial passage threaded` to connect with the tube extension 8 at its upper end. On its inner end it has a ground seat to receive the upper end of the perforated nlpple 9 upon the eduction tube. f

The eduction tube 6 is connected with the nipple 9 by the coupling I0 which fits in a seat upon the flange or partition 5 and forms a seal therewith. The lower end cf the tubing is extended downwardly to be submerged the desired amount within vthe liquid II in the well'. The lower end of the tube is closed by a cap I2 perforated t0 admit liquid and gasto the tube. l "Theplungerisshownat' andisof theusual g oomtmction withan upwardly closing valve I4,

the stem I5 of which extends below the body of the valve support I6.

Spaced the desired distance above the lower end of the tube 6 is a valve housing I1 which is coupled into the tubing as shown. One wall of the housing is made thick as shown in Fig. 2. This wall has a chamber I8, closed on its outer side by a plate I9 which may be welded in place. From the chamber I8 are two opposite lateral branches providing valve compartments 20 1 formed by a cylindrical bore extending trans versely of said chamber. From these compartments are a plurality of downwardly and inwardly formed passages 2| leading to the interior of the housing. See Fig. 4. 15

The valve includes a cylindrical head 22 which lits closely, but rotatably, within the bore 20. The ends within the .compartments are formed hol-,-` low and on the lower side are openings 23 from the hollowed recesses, arranged to be brought 20 into registration with the passages 2l when the valve is opened. The head 22 of the valve has a sleeve 24 thereon which `may be secured rotatably thereon by a set screw 26. On the side of the sleeve 24 facing inwardly is a iinger 25 25 projecting into the path of travel of the plunger. Above the valve the sleeve 24 has'attachment at 2'I to -a coiled spring 28 supported in the upper portion of chamber I8. Said spring tends to holdthe sleeve in position with the finger ex- 30 tending radially inward. As will .be seen in Fig.

3 the set screw l2li lits through a slot 29 in the sleeve 24 and permits only a limited rotative movement oi the sleeve on the valve.

At the upper end of the well the dischrage pipe 35v 4 has a main branch 30 leading to the upper end of a tank or container 3| so that the fluidfrom the well will be discharged, on each stroke, into said tank.

The liquid will drain out of said tank through 40 the pipe 32 in which is placed the choke valve 33 to control the rate of drainage. Beyond the lchoke valve 33 a pipe .34 is connected so as to allow escape of gas from the upper end of the tank with which said pipe 34 is connected. 45

There is an automatic valve 35 o1' common construction connectedin the gas line 34. The stem of said valve is connected with a diaphragm set in the housing 36. The outer end of said housing is connected by a. bypass line 31 with the dis- 50 charge line 4, so as to receive the well pressure thereon.

The upper end of the eduction pipe extension -may be connected with the discharge line 3l` through pipe 3 8 by opening valve 3 8, which is 55 normally closed. When the. valve is opened the plunger may pass upwardly above valve which may then be closed to catch the plunger when it becomes desirable to do so.

In operation the plunger I3 with its load of liquid is raised in the eduction tube by the pressure of gas or air in the casing I entering below -thev plunger after depressing the head of liquid I I outlets 4 and 30 to the container 3| the fluid' pressure will also act through bypass 3'I` upon valve 35 and 'close it and hold it closed until the fluid pressure is decreased below a predetermined value, whereupon said 'valve will open. The plunger will pass the outlet and will be stopped by iiuid compressed in the dead upper end of the extension 8 and the valve in the plunger will be forced open. The plunger will then start to fall and as the exhaust of the gas in the tube is prevented by the closed valve 35, the plunger will be unimpeded by escaping gas.

The plunger, in its fall, will engage the finger 25 upon the valve and move it downwardly. This will rotate the valve into the position shown in Fig. 4 and the entrance of further gas to the tube therethrough will be prevented.

It willbe noted thatY the spring 28 will hold the linger .25 upon the valve sleeve pointing inwardly, but, due to the lost motion provided by the engagement of the set screw 26 in the slot 29, the valve will be allowed to remain in the position into which it was turned until a partial rotation in the opposite direction is imparted thereto by the plunger. Thus the upward movement of the plunger will open the valve and a downward movement. of the plunger pastsaid nger 25 will close the valve.

The charge of liquid in the tank 3l will drain out at the rate desired under control of the choke A33 which will be set to release the liquid and then some of the gas by the time the plunger has fallen to the desired depth. As the gas pressure is thus decreased by the escape of gas from the well, the valve 35 will be forced `open and the remaining gas will discharge quickly through the 'pipe 34j t As the escape'of gas into' the tube from the casing is4 closed by valve 22, the pressure of the gas will quickly build up in the casing and depress the liquid level so as to again permit the gas to enter below the plunger as before and a new cycle of operations will be initiated.

The use of the automatically operated valve 22 will save gas which would be otherwise wasted because the pressure of the gas need not be so great throughout the cycle where it does not need to keep the liquid depressed to the lower end of the tube throughout the upward lifting of the load. When the valve 22 is closed on the downward stroke, the pressure of gasis not allowed to exhaust from the casing, but only the gas in 'the tube may escape.

Further, the entrance of liquid below thel plunger forv the next load is permitted while the plunger is being lifted. The gas in the casing not interfere with the entrance of the liquid into the well. Hence, when the plunger reaches bottom, it will be ready almost at once to start upon its next upward stroke. We thus accomplish a faster operation-of the device and also save in the. amount of gas necessary for operation.

What is claimed is:

1. A plunger lift device including an eduction tube having fluid openings at its lower end, a iiuid outlet adjacent its upper end, and a plunger movable from end to end of said tube, in combination with a gaseous fluid inlet in said tube at a level spaced rupwardly from its lower end, a valve in said inlet arranged to be opened by upward movement of said plunger past the same and to be closed by downward movement of said plunger past the same.

2. A plunger lift device including an eductio tube having iiuid openings at its lower end, a uid outlet adjacent its `upper end, and a plunger movable from end to end of said tube, in combination with a gaseous fluid inlet in said tube at a levelv spaced upwardly from its lower end, a valve in said inlet, a finger on said valve projecting into thepath of said plunger whereby said valve may be operated by said plunger to open and lclose. Y

3. A plunger lift device including an eduction tube' having fluid openings at its lower end, a fluid outlet adjacent its upper end, and a plunger movable from end to end of said tube, in combination with agaseous fiuid inlet in said tube at a level spaced upwardly from its lower end, a valve in said inlet, means on said valve to be engaged by said plunger on its upward and downward movement in said tube to open and close said valve, and means in said outlet to control the release of gaseous fluid from within said tube and past said valve from the outside thereof.

4. A plunger lift device including an eduction tube having iiuid openings at its lower end, a iiuid outlet adjacent its upper end, and a plunger movable from end to end of said tube, in combination with a gaseous fluid inlet in said tube at a level spaced upwardly from its lower end, a valve in said inlet, a finger on said valve, and means to hold said finger normally extending inwardly into the path of said plunger to be engaged by saidA plunger, whereby said plunger may open and close said valve.

5. A plunger lift device including an eduction tube having uid openings at its lower end, a. fluid outlet adjacent its upper end, and a plunger movable from end to end of saidl tube, in'combination with a gaseous fluid inlet in said tube at a level spaced upwardly from its lower end, a valve in said inlet, means on said valve cooperating with said plunger to control the position o1' said valve, and means to control the time of release of gaseous pressure fluid from said tube after each upward stroke of said plunger so that said plunger in dropping may close said valve before said pressure is released;

6. In a plunger lift device an eduction tube, a plunger movable by gaseous fluid pressure from end to end of said tube, a fluid inlet at the lower end of said tube, a fluid outlet at the upper end thereof, an opening in said tube at a level above the lower end, and a valve in said opening adapted to be opened and closed in response to the upward and downward movements respectively of said plunger in said tube.

7. In a plunger lift ,device an eduction tube, a plungermovable by gaseous fluid pressure from end to end of said tube, a fluid inlet at the lower end of said tube, a. iiuid outlet at theupper end thereof, an opening in said tube at a level above the lower end, a valve in said opening automatically operated by contact oi said plunger therewith, and a control device in said outlet to delay the escape of pressure fluid from said tube after each upward stroke of said plunger until said plunger has completed the greater part of lts return stroke and close said valve.

8. In a plunger lift device an eduction tube, a plunger movable by gaseous fluid pressure from end to end of said tube, a uid inlet at the lower end of said tube. a fluid outlet at the upper end thereof, an opening in said tube at a level above the lower end, a Valve in said opening automatically controlled by contact with said plunger to open and allow entrance of pressure fluid behind said plunger on its upward stroke and to close oi further entrance of pressure fluid when said plunger passes said valve on its downward stroke.

9. In a plunger lift device, an eduction tube having fluid inlets at its lower end, a plunger movable by uid pressure from end to endV of said tube, a valve housing in said tube spaced at a predetermined levelabove said lower end, a valve in said housing adapted to control passage of iluid to said tube, a finger on said` valve, means to hold said finger in a position projecting int-o the path of said plunger, the contact of said of fluid to said tube,l including a rotatable valve body, a n'ger secured rotatably to said body, means to limit the relative rotation of said finger on said body, inlets controlled by the rotation of saidy body, said valve being moved in response to the engagement of said plunger with said finger.

1l. In a plunger lift device for a deep well including an eduction tube and a plunger movable freely in said tube from end to end thereof, the method including depressing ythe liquid level in said well to permit entrance of gaseous Vfluid below saidplunger and thus to move said plunger upwardly, then introducing pressureuid to said tube at a level above the lower end of said tube and againsubmerging said lower end in liquid, discharging liquid above said plunger, regulating the rate of discharge of said liquid to prevent discharge of pressure fluid until said plunger has -fallen a predetermined distance, and then closing off the entrance of pressure fluidto said tube above its lower end.

HAROLD W. FLETCHER. RALPH NEUHAUS. 

